Self-Healing Laminated LLZO/Reduced Graphene Oxide/LLZO Composite Solid-State Electrolytes for Arresting Dendrite Penetration in Solid-State Batteries

Solid state lithium metal batteries using inorganic solid electrolytes are widely regarded as next-generation devices that can enable substantial improvements in energy density. However, the performance of these electrolytes is currently limited as they are largely unable to hinder the propagation and penetration of lithium metal dendrites that lead to the shorting of cells at practical current densities. In this work, we propose a novel architecture for solid state electrolytes, using a laminated composite structure consisting of reduced Graphene Oxide (rGO) interlayers that are embedded inside of Tantalum-doped LLZO (Li_6.4La₃Zr_1.7Ta_0.3O₁₂) to create a stable layered solid-state battery that effectively arrests dendrite penetration. Testing of these interlayer-engineered LLZO electrolyte with symmetric lithium metal electrodes, leads to critical current density increases of more than 7 times at room temperature. FEM simulations of these multi-layered structures were also conducted to provide insight into designing a broader range of laminated solid electrolyte architectures. Our results indicate that solid state electrolytes can be engineered with interlayers to deflect dendrites and improve critical current densities.